I have a requirement to provide a link on a detail page to a list of related records. The link would have to take the user to a specific saved list and filter the list for those records related to the record being drilled from.
In our case, they are all custom objects but a similar example would be putting a link on the Account Detail page that would navigate the user to a list of contacts associated to that account. The related region can not be used because the users need to view more than 9 fields. And a report can not be used because the users need to be able to edit the records in the list.

If your requirement is to just VIEW a list of Related Records that meet your criteria, you could probably achieve it by building a report and navigating to it using the Web Link by passing the parameters to the report through the URL.

If your Customer insists on navigating to a list of related records through a Custom List (May be because they want to edit a set of records etc...)
You could create a couple of Custom Lists that meet all possible criteria you might have.

Eg: All US Contacts
All UK Contacts

On the click of the weblink you could pass the URL of the Custom List. It will look something like this.
https://secure-ausomxXXX.crmondemand.com/OnDemand/user/ContactList?ContactList.LAYOUT=Contact+List+AllUKContacts&ContactList.LAYOUTID=XXXX-JHU0G&OMTGT=ContactList&OMTHD=ListPostBack&ContactList.EDITFLAG=Y

Hi Royston - thanks for your response. The customer does need to navigate to a specific custom list so that a set of fields to be edited can be included. However, they also need the list filtered to show only records related to the parent record. So to use your example - they would need a link on Account record A that navigated them to custom list "All US Contacts", with that list further refined to show only US Contacts related to Account A. And it would have to be dynamic so they could do the same from any account. The functionality they need is very similar to passing a paramter to a report, but since they need to be able to edit the records in the list, a report won't meet their needs.

You need to edit the records, does not necessarily eliminate the report option.

Create a report and pass the account ID (as an example).
This report is visible on the account page related info sections as a custom applet.

in the report itself you can make the Contact last name column with an action link which drills down to the actual record detail page and allows you to edit the record. (only works on account,
opportunity, contact, campaign, lead, service request, or user record)

else

You can also add a custom column with some JS which can show the edit button text and take you directly to the edit page of that record. (I do not have the technical details on how tis can be done)